Example 1 
From [1]}, we take the example of formulating the well-known
Closed World Assumption via ELP rules. Two formulations of the CWA have been
proposed in this context. In [2]}, a rule for CWA is proposed
that, in the language of ELPs, can be formulated as
\( p^{\prime } \leftarrow \lnot \mathbf {not}\,\lnot p. \) 
